CVE-2026-43617

MEDIUMPre-NVD 4.84.8—
EchelonGraph scoreMEDIUM confidence

Score 4.8 from GitHub Security Advisory published 2026-05-20. NVD baseline CVSS 4.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
4.8
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 4.8Exploit: NoneExposed: 0

A fix is available — apply it.

Rsync version 3.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon's hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing connections from hostnames that administrators intended to deny when reverse DNS resolution fails and defaults to UNKNOWN.

CVSS v3
4.8
EG Score
4.8(medium)
EG Risk
—
EPSS
20.3%
KEV
Not listed

Published

May 20, 2026

Last Modified

July 14, 2026

Advisory Details (3)

Auto-updated May 20, 2026
Patch available. Sources: github.
generic

Rsync < 3.4.3 Authorization Bypass via Hostname Resolution | Advisories | VulnCheck

https://www.vulncheck.com/advisories/rsync-authorization-bypass-via-hostname-resolution
github Patch Available

rsync: hostname/ACL bypass on DNS-lookup failure · Advisory · RsyncProject/rsync · GitHub

https://github.com/RsyncProject/rsync/security/advisories/GHSA-rjfm-3w2m-jf4f
generic

Release v3.4.3 · RsyncProject/rsync · GitHub

https://github.com/RsyncProject/rsync/releases/tag/v3.4.3

Vendor Advisories for CVE-2026-43617(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntursync (3.4.1+ds1-7ubuntu0.2) @ resolute2026-06-29ubuntu
ubuntursync (3.1.0-2ubuntu0.4+esm3) @ trusty2026-06-29ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(2)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 8× in last 7d / 39× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 123 total refreshes for this CVE.

  1. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:24 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-19 14:31 UTCEPSS rescore
  5. 2026-07-19 02:29 UTCEPSS rescore
  6. 2026-07-18 10:04 UTCEPSS rescore
  7. 2026-07-17 23:29 UTCOSV refresh
  8. 2026-07-16 17:03 UTCEPSS rescore
  9. 2026-07-15 16:57 UTCEPSS rescore
  10. 2026-07-15 02:00 UTCEPSS rescore
  11. 2026-07-13 22:30 UTCEPSS rescore
  12. 2026-07-13 06:13 UTCEPSS rescore
  13. 2026-07-12 05:46 UTCEPSS rescore
  14. 2026-07-11 08:27 UTCEPSS rescore
  15. 2026-07-09 19:10 UTCEPSS rescore
  16. 2026-07-08 15:16 UTCEPSS rescore
  17. 2026-07-07 13:46 UTCEPSS rescore
  18. 2026-07-06 16:27 UTCEPSS rescore
  19. 2026-07-06 02:23 UTCEPSS rescore
  20. 2026-07-05 02:30 UTCEPSS rescore
  21. 2026-07-04 06:31 UTCEPSS rescore
  22. 2026-07-01 15:07 UTCEPSS rescore
  23. 2026-06-30 23:22 UTCEPSS rescore
  24. 2026-06-29 20:33 UTCVendor advisory
  25. 2026-06-29 20:33 UTCGHSA enrichment
Show 75 more
  1. 2026-06-29 14:06 UTCEPSS rescore
  2. 2026-06-28 14:07 UTCEPSS rescore
  3. 2026-06-28 04:56 UTCEPSS rescore
  4. 2026-06-27 20:19 UTCVendor advisory
  5. 2026-06-27 20:19 UTCGHSA enrichment
  6. 2026-06-27 03:08 UTCEPSS rescore
  7. 2026-06-26 19:41 UTCVendor advisory
  8. 2026-06-26 19:41 UTCGHSA enrichment
  9. 2026-06-25 16:25 UTCVendor advisory
  10. 2026-06-25 16:25 UTCGHSA enrichment
  11. 2026-06-25 13:49 UTCEPSS rescore
  12. 2026-06-25 13:49 UTCEPSS rescore
  13. 2026-06-24 14:05 UTCEPSS rescore
  14. 2026-06-23 21:33 UTCEPSS rescore
  15. 2026-06-22 14:25 UTCEPSS rescore
  16. 2026-06-22 14:25 UTCEPSS rescore
  17. 2026-06-21 14:56 UTCEPSS rescore
  18. 2026-06-21 14:56 UTCEPSS rescore
  19. 2026-06-21 01:59 UTCEPSS rescore
  20. 2026-06-19 19:25 UTCEPSS rescore
  21. 2026-06-18 17:52 UTCEPSS rescore
  22. 2026-06-18 17:52 UTCEPSS rescore
  23. 2026-06-17 20:05 UTCVendor advisory
  24. 2026-06-17 20:05 UTCGHSA enrichment
  25. 2026-06-17 17:53 UTCEPSS rescore
  26. 2026-06-16 20:21 UTCVendor advisory
  27. 2026-06-16 20:21 UTCGHSA enrichment
  28. 2026-06-16 17:52 UTCEPSS rescore
  29. 2026-06-15 17:49 UTCEPSS rescore
  30. 2026-06-15 15:53 UTCVendor advisory
  31. 2026-06-15 15:53 UTCGHSA enrichment
  32. 2026-06-14 14:10 UTCVendor advisory
  33. 2026-06-14 14:10 UTCGHSA enrichment
  34. 2026-06-13 23:00 UTCEPSS rescore
  35. 2026-06-13 14:50 UTCVendor advisory
  36. 2026-06-13 14:50 UTCGHSA enrichment
  37. 2026-06-12 23:12 UTCEPSS rescore
  38. 2026-06-12 23:12 UTCEPSS rescore
  39. 2026-06-12 15:55 UTCVendor advisory
  40. 2026-06-12 15:55 UTCGHSA enrichment
  41. 2026-06-11 16:46 UTCVendor advisory
  42. 2026-06-11 16:46 UTCGHSA enrichment
  43. 2026-06-11 14:00 UTCEPSS rescore
  44. 2026-06-10 22:18 UTCEPSS rescore
  45. 2026-06-10 17:17 UTCVendor advisory
  46. 2026-06-10 17:17 UTCGHSA enrichment
  47. 2026-06-10 13:22 UTCEPSS rescore
  48. 2026-06-10 13:22 UTCEPSS rescore
  49. 2026-06-09 18:23 UTCVendor advisory
  50. 2026-06-09 18:23 UTCGHSA enrichment
  51. 2026-06-08 19:29 UTCVendor advisory
  52. 2026-06-08 19:29 UTCGHSA enrichment
  53. 2026-06-08 14:17 UTCEPSS rescore
  54. 2026-06-08 14:17 UTCEPSS rescore
  55. 2026-06-07 19:20 UTCVendor advisory
  56. 2026-06-07 19:20 UTCGHSA enrichment
  57. 2026-06-07 15:25 UTCEPSS rescore
  58. 2026-06-07 15:25 UTCEPSS rescore
  59. 2026-06-06 20:26 UTCVendor advisory
  60. 2026-06-06 20:26 UTCGHSA enrichment
  61. 2026-06-06 13:47 UTCEPSS rescore
  62. 2026-06-06 13:47 UTCEPSS rescore
  63. 2026-06-05 22:47 UTCEPSS rescore
  64. 2026-06-05 21:32 UTCVendor advisory
  65. 2026-06-05 21:32 UTCGHSA enrichment
  66. 2026-06-05 06:10 UTCEPSS rescore
  67. 2026-06-05 06:10 UTCEPSS rescore
  68. 2026-06-04 22:38 UTCVendor advisory
  69. 2026-06-04 22:38 UTCGHSA enrichment
  70. 2026-06-04 13:12 UTCEPSS rescore
  71. 2026-06-04 13:12 UTCEPSS rescore
  72. 2026-06-03 23:44 UTCVendor advisory
  73. 2026-06-03 23:44 UTCGHSA enrichment
  74. 2026-06-03 00:49 UTCVendor advisory
  75. 2026-06-03 00:49 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-43617?
CVE-2026-43617 is a medium vulnerability published on May 20, 2026. Rsync version 3.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon's hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing…
When was CVE-2026-43617 disclosed?
CVE-2026-43617 was first published in the National Vulnerability Database on May 20, 2026, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43617 actively exploited?
CVE-2026-43617 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 20.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-43617?
CVE-2026-43617 has a CVSS v3 base score of 4.8 (NVD).
How do I remediate CVE-2026-43617?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43617, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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